This proposal requests funds for a state-of-the-art, computer- control system for auditory physiological experiments. The proposed system consists of a Masscomp computer system that is ideally suited for fast input/output of analog data and a variety of programmable electronic devices that control computer-generated acoustic stimuli and process acoustic, electric, and mechanical signals recorded from the ear and the brain of experimental animals. This system will serve a tightly-knit community of investigators who work on all stages of the auditory system from the external ear to central neural pathways of the brainstem. It is a prototype for a new generation of data acquisition systems destined to replace 15-year old systems based on PDP-8E computers that have become obsolete and overextended. The new system will be built around an existing, high-quality sound-proof chamber that has been waiting to be fully instrumented. New trends in auditory physiology create a demand for a facility with capabilities beyond those presently available. Some of these new features are computer generation of acoustic and electric stimuli, multiple, precisely- synchronized stimulus and response channels, flexible processing of discrete event data such as neural discharges, and sufficient computational power to allow online test of predictions from mathematical models with data from physiological experiments. The proposed system will enable investigators to have all of these capabilities and bring physiological studies to a new level of flexibility an efficiency.